Repulsion-motor-control system.



O. B. HOFFMANN.

REPULSION MOTQR CONTROL SYSTEM.

APPLICATION 111,111) 1111111 19, 1911.

1,078,439, Patented Nov. 11, 1913.

Q 2 SHEETS-SHEET 1. R @J QE (A G. B. HOFFMANN.

REPULSION MOTOR CONTROL SYSTEM.

APPLICATION FILED 111111: 19, 1911.

Patentd Nov. 11, 1913.

2 SHEBTSSHEET 2.

, Snow/whoa @Qyg-p Med M 041/m&%

T: M 1 How r1213 Q iz UNITED STATES PATENT oFFroE.

CHARLES B. HOFFMANN, 0F CINCINNATI, OHIO.

REPULSION-MOTOR-CONTROL SYSTEM.

To all whom it mm concern:

Be it known t at I, CHARLES B. Horr- MANN, a citizen of the United States, and a resident of Cincinnati, in the county of Hamilton and State of Ohio, have invented certain new and useful Improvements in a Repulsion-Wlotor-Control System, of which the following is a specification.

The invention relates to electrically operated block signaling systems, more particularly those operated through the agency of analternating electric current.

The invention has particular reference to systems in which atrack is divided into blocks of suitable length, insulated from one another, and in which at .thebeginning of each of said blocks suitable semaphore signals are provided, the signal arms of which are arranged to be power driven, that is to say, by means of an alternating current motor.

The invention has for its object the control of the-said'mOtOr for operating the semaphore arms, more particularly to effect a power hold-clear as well as a power return of the semaphore arms.

The nature of the invention will be best understood when described in connection with the accompanying drawings, in which Figure 1 is a diagrammatic view illustrating the general arrangement of the various circuits for a power hold-clear and "gravity return system. Fig. 2 is a fragmentary diagrammatic view illustrating a modification in the hold-clear arrangement. Fig, 3 is a similar view illustrating the arrangement for a power hold-clear and power return, and operated through two auxiliary brushes. Fig. 4 is a similar view illustrating a power hold-clear and power return operated with but one auxiliary brush. Fig. 5 is a fragmentary diagrammatic view illustrating a modification in the manner of operating the motor. Fig. 6 is an elevation of the motor controller and driving gear for operating a semaphore arm.

Similar characters of reference designate corresponding parts throughout the several views.

Referring now to Fig. 1 of the drawings, 20 and 21 designate the track rails which are Specification of Letters latent.

Application filed June 19, 1911.

Patented Nov. 1 1, 1913.

Serial No. 634,065.

insulated from one another by suitable insulation 22, providing blocks 25, 26, 27, etc., of suitable length. A train 28 is assumed to be located on the block 27 and to be traveling in the direction indicated by the arrow. Semaphores 30, 31, 32, etc., of wellknown type, are located at the beginning of each of the corresponding blocks 25, 26, 27, etc., and their respective arms 35, 36, 37, etc., are normally inclined to the vertical at an angle of 30, which position designates a safe condition of the corresponding block (as in the case of blocks 25 and 26). To assume a horizontal or danger position (as is the case of arm 37), the arms are obliged to rotate downwardly 60. This downward movement is usually effected by gravity, as in the arrangement shown in Fig. 1; but the present invention contemplates also a positive or power return of this arm to the danger position.

Suitable mains 40 carrying alternating current are arranged along the tracks and supply, through transformers 41, 42, and 43, etc., provided respectively with double secondaries 44, 46, 47; and 48, 49, etc., the power for the usual track relays 50, 51, 52, etc., of the corresponding blocks, as well as the power for the operating motors 53, 54, 55, etc., of the corresponding semaphores. The signal relays are of the wellknown type and their connections are made in the usual manner, as shown, and need no further explanation.

The motors 53, 54, 55, etc., employed to operate the corresponding semaphore arms 35, 36, 37, etc., are of the repulsion type. Such motors consist usually of a stationary primary member or stator and a rotatable secondary member or rotor, the latter being in the nature of a direct current armature, upon the commutator of which rest brushes in positions 180 electrical degrees apart and directly short-circuited upon themselves. These brushes are displaced a given angle from the line of polarization of the primary magnetism. For the purposes of the present invention, however, the power may be directlyapplied across the brushes of the rotor and the stator short-circuited, as illustrated in Fig. 5. The brushes themselvesmay, furthermore, be of considerable width. as shown in Fig. 1, to

short-circuit a plurality of armature windings. The usual form of brush, however, is that illustrated in Figs. 2 to 5, the same being of a width equal to or less than a commutator segment.

The actuating mechanism for the semaphore arms is of the well-known type, as illustrated in Fig. 6; and consists of a shaft 60 driven through an intermediate train of gearing 61 from the shaft 60 of a motor 53 which is mounted in a suitable casing 62. Shaft 60 rotates in suitable bearings provided by the casing 62, and carries in addition to the arm 35 a circuit controlling device 63, having contact pieces 163, partaking of the motion of said shaft and semaphore arm 35. This controlling device is of the usual and well-known type (the electrical connections to which, however, have not been shown) adapted to close and open in.

the usual manner due to its oscillation, the various electrical clrcults as Wlll hereinafter Y be set forth. The pinion 64 on shaft 60 and of the train gearing 61 is preferably made segmental, and is provided with a pin 65 to engage a limiting stop 66 secured to the casing.

In Fig. 1, the motors 53, 54, 55, etc., are of the type with short-circuited brushes 68 and 69, which brushes are of considerable width and the field or primary 70 is connected through the corresponding relays 50, 51,52, etc., with the source of power from malns 40.

\Vhen a relay is open, due to the shortcircuiting of the same, as inthe case of relay 52, through the wheels of a train on a corresponding block, the primary circuit of the motor is opened and the corresponding semaphore arm 37 drops under theaction of gravity to the horizontal position shown. This movement of the semaphore arm correspondingly operates the circuit controlling device, which moves therewith to close the contact 73 through which the brushes 68 and 69 of the motor 55 are short-circuited. This condition is maintained until the block is again clear, when the relay closes. Power will then be restored to the primary 70, causing the motor to operate, for the brushes will be short-circuited through switch 73 until the semaphore has been elevated, for example 58. At this point, the circuit controller which has moved with the corresponding semaphore arm will have opened the brush circuit through the switch 73, for example as in the case of switches 71 and 72. The momentum of the upwardly moving semaphore arm will carry the same a few degrees farther to its safe position 30 from the vertical, or 60 from the horizontal, the movement being arrested by the pin 65 and stop 66. This slight additional movement, however, has opened the brush circuit and the samaphore arm will, therefore, naturally tend to move downwardly until the circuit were again closed. To prevent such downward movement of the arm, except when the primary circuit is opened through the relay 52, and to hold the semaphore arm in elevated and safe position, the brushes 68 and 69 are designed to be of considerable width so as to span a number of commutator segments. Thus, when the brush circuit is open through switch 73, enough armature windings will be short-circuited by the said brushes to provide a sufficient holding torque of the motor to overcome the counter torque of the semaphore arm tending to cause the same to return to a horizontal position. The semaphore arm will thus be held in elevated or safe position until power is cut off from the motor, as for example by the opening of the primary circuit through its relay when a train is on the corresponding block. The arm then drops under the action of gravity to a horizontal or danger position, as explained, and remains in this position until the train has cleared the block to cause the relay to close the primary circuit.

In place of the wide brushes, the same effect may be secured by means of an additional brush 75, Fig. 2, cooperating with the brushes 76 and77, which brushes as well as brush are of the usual width, viz: slightly less than the width of a commutator segment. In this embodiment, an additional switch 78 is required, the same being adapted to be closed by the circuit controller after the arm has moved upwardly 58, that is to say that at the same time that the brush circuit is opened at switch 73. Switch 78 in closing, short-circuits the armature windlngs included between the brushes 76 and 75 and produces thereby the required holdlng torque to maintain the sa-mephore arm in its elevated position.

In many instances it is desirable to return the semaphore arm to danger position by power and not depend on the gravity action merely; for it may occur that the arm will freeze in'its elevated position and therefore will not respond when the train is in the corresponding block. To accomplish this, an additional brush 80, Fig. 3, is required as well as additional switch 81. The relay 52 is, also, provided with additional contacts 82, 83, and 84:. The same result may also be accomplished by means of the single additional brush 75, provided certain variations in the circuit are effected.

In case two additional brushes 75 and 80, Fig. 3, in addition to the usual brushes 76 and 77, are employed to effect the holdclear and power return of the semahore arm, lower contacts 83 are provided in connection with relay 52 to close the primary circuit also during the deenerglzed condition of the said relay. A switch 81,

however, is included in this additional circuit for closing the primary circuit, and is adapted to be closed through the action of the controller after the arm has moved upwardly 5. Upon the downward movement of the arm and under the power actuation, the power will thus be maintained up to within 5 of the horizontal or danger position. \Vhen this point is reached, switch 81 is opened and opens thus the primary circuit, the semaphore arm, however, continuing to the horizontal position under its own momentum. Upon the upward movement of the arm when the block is clear the power hold-clear is effected in precisely the same manner as in the embodiment set forth in Fig. 2, the circuit, however, having included therein the relay contact 82 which is closed so long as the block is clear. hen the relay is deenergized, Fig. 3, that is to say when a train enters the corresponding block, the contact 84 of said relay is closed and short-circuits thereby the windings of motor includedbetween the brushes 76 and 80. This will produce a reverse torque on the motor and thereby lower the semaphore arm to horizontal posit-ion,the motor being rendered inoperative through opening of switch 81 when the arm is within 5 of its danger posit-ion.

In the embodiment set forth in Fig. 4, a contact 84 short-circuits the armature windings of motor 55 included between brushes and 7 7 to effect the desired reverse torque for the purpose of returning the semaphore arm to its danger position. Brush is omitted, being unnecessary in view of the short-circuiting of the armature windings between brushes 75 and 77 to produce the reverse torque.

In Fig. 5 the rotor 85 of motor 55, instead of the stator 86, is made the primary of said motor, power being led to the same through brushes 87 and 88 arranged 180 electrical degrees apart. The switching mechanism is otherwise precisely the same as that described in connection with Fig. 4 for efi'ecting a power hold-clear and power return of the semaphore arm. Instead of short-circuiting the various number of armature windings, however, as in the embodiment set forth in Fig. 4, corresponding turns of the field winding or stator 86 are arranged to be short-circuited.

The system herein set forth for operating the semaphore arms by means of a repulsion motor greatly simplifies the necessary mechanism, in that such devices as centrifugal governors, springs, cams, ratchets, choke coils and the like may be dispensed with and the contacts on the drum controller reduced in number. Furthermore, the brushes may be set to the best operating position and the maximum effect obtained. Less actual power is required to hold clear with the system hereinbefore described and there is less heating of the motor. For the power return no special auxiliary windings'are necessary on the motor, as well as no phase splitting device or outside resistance or reactance to limit the current. The only additional part is the extra brush and holder which can be put on at practically no cost and will serve for both hold-clear and power return. These devices can easily be installed in systems already in operation withoutinvolving any great expense or disturbing the operation.

I claim 2- 1. The combination with a repulsion motor; of means to control the circuit of one of the elements of said motor; and means controlled by the movement of the rotor of said motor to vary the electrical connections of the other of said elements to hold the rotor in predetermined position.

2. The combination with a repulsion m0- tor; of means to cdntrol the circuit of one of the elements of said motor; and means cont-rolled by the movement of the rotor of said motor to vary the electrical connections of the short-circuited element to hold the rotor in predetermined position.

3. The combination with a repulsion motor; of means to control the circuit of one of the elements of said motor andmeans controlled by the movement of the rotor of said motor to open the short circuited element of said motor.

4. The combination with a repulsion motor; of means to open the short circuited element of said motor; and means to short circuit a predetermined number of coils of the said short circuited element to hold the rotor of the motor in predetermined position.

5. The-combination with a repulsion motor; of means to open the short circuited element of said motor; a normally open auxiliary circuit connected with said short circuit-ed element; and means operated by the movement of the rotor of said motor to close the said auxiliary circuit.

" 6. The combination with a repulsion motor; of means to open the short circuited element of said motor; a normally open auxiliary circuit intermediate of the short circuited connection of said motor; and means operated by the movement of the rotor of said motor to close the said auxiliary circuit.

7. The combination with a repulsion motor, having two brushes one hundred and eighty electrical degrees apart and normally connected together; of means to open said connection; a brush intermediate of said two brushes; and means to connect said brush with either of the said normally short circuited brushes.

8. The combination with a repulsion mo tor, having two brushes one hundred and eighty electrical degrees apart and nor- Signed at Rochester in the county of Monmally connected together; of means to open roe and State of New York this 16th day of said connection; a brush intermediate of June A. D. 1911.

said two brushes; and means operated by CHARLES B. HOFF MANN the movement of the rotor of said motor to Witnesses: connect said brush with either of the said FLORENCE E. COOPER,

normally short circuited brushes. CHARLES W. PYATT. 

